1. Field of the Invention
This invention pertains to an improved design of a raised floor system that is also known as: an elevated floor, an access floor, a false floor, a pedestal floor, a cellular floor or a computer floor system.
2. Related Art
A raised floor system is used where it is desirable to maintain ready access below the floor surface to cables, wiring, ducting and other building services. Access floor assemblies of the general class of the present invention are well known in the prior art. Such flooring has been manufactured for many years and is used extensively in computer and control rooms, and more recently in general office areas.
A raised floor system generally consists of a plurality of floor panels that are supported a short distance above a base floor by support members. The floor panels form a raised floor enclosing a space between the raised floor surface and the base floor. The space can be used for the distribution of air, ductwork, electrical wiring, communication wiring and computer cables, as well as many other services. Each panel is individually removable for easy access to the services below and to allow quick, low-cost relocation of service outlets.
Some prior raised floor designs include pedestals with stringers therebetween on which floor panels are supported. The stringers serve to make the floor more rigid, but create a problem in laying additional wiring or ductwork since both the floor panels and the stringers need to be removed to allow access to the space.
Floor panels in much of the prior designs are maintained in position by simple gravity placement, or by being bolted to pedestals or to a combination pedestal and stringer network. As such, in many of these prior designs the floor panels settled after time which resulted in an uneven floor surface prone to rocking when loads were applied to the floor surface. By adjusting each pedestal, corrections could be made to account for the settling of the floor panels but this process is often time consuming and disruptive of office routine, as well as expensive.
To address this concern, in U.S. Pat. No. 4,438,610 to Fifer, free-standing pedestals are used to support interlocking floor panels above the base floor. During installation, pedestals are arranged along the base floor in a predetermined array and then floor panels are interlocked and secured to the pedestals. Thus, the precise location of the pedestals is only determined once the floor panels are installed. Adhesive is then used to secure the pedestals to the base floor.
Although the floor surface of the raised floor system described in U.S. Pat. No. 4,438,610 is sturdy and resists settling/deformation, the design and process of installing a raised floor according to this design is tedious and time consuming due to the careful measuring and layout required to assure pedestal placement at each corner of a floor panel plus the subsequent trial and error involved in getting the pedestals correctly positioned during actual installation. In addition, each pedestal must then be individually secured to the base floor and leveled.
To address the problems associated with pedestals and/or stringers, U.S. Pat. No. 4,905,437 to Heather suggests a plastic floor support module of unitary construction. The module comprises a plurality of support props extending upward from an integral frame arrangement with integral connection means for joining the module to a support prop of an adjacent floor support module. Support props are formed to accept a threaded fastener by which the corner of a floor panel may be secured and/or to support the underside of the floor panel. This configuration minimizes the necessity of leveling the floor panels and provides better support for the floor panels since each floor panel rests on support props at its corners and at various points about its interior area.
However, installation and repair of the flooring system disclosed in U.S. Pat. No. 4,905,437 is difficult due to the unitary nature of the floor support module. The floor support modules interconnect one to another forming an array to which the floor panels are secured. There is not a one-to-one relationship between any given floor support module and floor panel. Thus, positioning of floor panels is dependent on the location of the nearest support prop to each of its four corners. Often times, a floor panel will not align with a support prop at each corner. This results from a variety of causes, including dimensional build which can occur as a consequence of incidental stretching of the unitary floor support module during installation, i.e., stretching that occurs when modules are laid and connected on the base floor and then lifted so that adhesive may be applied to the under surface of the module. When floor panels do not readily align with support props, subsequent positioning of the floor panels is often tedious and difficult because it requires reworking areas already installed.
In addition, if a support prop or module of the floor system described in U.S. Pat. No. 4,905,437 is damaged during or subsequent to installation, it requires that the entire module be removed which can and often does entail the removal of numerous panels. This increases installation and repair time, as well as, the costs associated therewith.
Accordingly, what is needed is a raised floor system that incorporates a stable raised floor surface with a supporting structure that allows ready access to the space created therein. In addition, the raised floor system must be designed for ease of installation over a base floor surface, as well as, allow for ease of subsequent repair.
To achieve the foregoing and other objects, and in accordance with the purposes of the present invention as embodied and broadly described herein, the raised floor system of the present invention provides a uniform floor surface above a base floor with space therebetween. The raised floor system comprises a low-profile base floor web assembly for installing on a base floor and floor panels that are secured thereto.
In the present invention, the base floor web consists of interconnected base floor web tiles. Each tile is comprised of elongate members integrally formed between connection pods and/or docking pods in a square grid-like arrangement. Connection pods are formed between elongate members along two sides of the tile, whereas docking pods are formed between elongate members on the remaining two sides of the tile. The connection pods are circular and the docking pods are semi-circular. However, connection pods and docking pods can be constructed in any complementing shape.
Further, adhesion pads are integrally formed between each elongate member and connection pod, as well as, between each docking pod and elongate member. At approximately the center of each adhesion pad is an aperture for receiving mastic or glue and on the underside of each adhesion pad are slightly raised radial lines. When the base floor web is installed on a base floor, mastic is injected through the apertures of each adhesion pad so that the mastic is applied under the adhesion pad and between the radial lines without lifting the web off the base floor. The slightly raised area created by the radial lines on the underside of the adhesion pad ensures that the mastic is not squeezed out once the weight of the floor panels is applied during installation, which is further described below.
Further, elongate members which form the perimeter of each base floor web tile have means for interconnecting with adjoining base floor web tiles to form the base floor web. The tile interconnection means comprises tabs and/or tab acceptors disposed on the perimeter elongate members of each base floor web tile. Thus, tab acceptors of one base floor web tile are positioned to correspond to and receive respective tabs of adjoining base floor web tiles. Elongate members which form the interior grid of the base floor web tile may be provided with cable tie-downs for securing cables, wires and similar items thereto.
An alternate embodiment of the base floor web tile is comprised of a plurality of perimeter members and interior members arranged in a grid-like manner. In this embodiment, perimeter members form a square perimeter and interior members form an interior grid of the base floor web tile.
Connection pods are integrally formed between perimeter members. Further, a connection pod is integrally formed between the interior members at a midpoint of the tile. Extending from each perimeter connection pod is a tile interconnector, with either a male snap connector or a female snap connector formed at the end thereof that is furthest from the connection pod. The male snap connector may include three connection points. When installed, female snap connectors of one base floor web tile snap onto the mating male snap connector of an adjoining base floor web tile. Thus, the female snap connectors and male snap connectors may be of various complementing shapes.
The base floor web tile provides a matrix into which floor panel supports are secured. A floor panel support is a hollow metal cylinder of uniform height with a raised lip around the circumference of its upper surface. The lipped upper surface has a slot formed through its center which is adapted to receive a corresponding floor panel support boss.
The boss serves as a receptacle for a threaded fastener as well as a cushion to the raised floor panels. Each floor panel support has a base portion that extends outward from and perpendicular to the main body of the floor panel support. The base portion has notches or small holes evenly spaced around its perimeter to resist the torque applied by the panel fastener during installation.
A plastic injection molding process called xe2x80x9cover-moldingxe2x80x9d or xe2x80x9cinsert-moldingxe2x80x9d is used to produce a base floor web tile assembly. To begin the over-molding/insert-molding process, floor panel supports are loaded into a mold in an automated injection-molding machine which performs the over-molding/insert-molding process. A plastic base floor web tile is then formed around the base portion of each floor panel support. A connection pod, including over-molded plastic stays, secures each floor panel support to the base floor web tile. The stays secure the base portion of the floor panel support to the web for installation and use but may still allow for the floor panel support to be removed and replaced. In addition, the notches in the bottom portion of the floor panel support are filled with plastic forming small xe2x80x9cpostsxe2x80x9d during the over-mold process which prevent the supports from rotating during installation. Similarly, the floor panel support boss is formed on the upper surface of each floor panel support during the over-mold process. The raised lip around the upper circumference of the floor panel support accommodates receipt of the boss.
During installation, a floor panel is laid horizontally across the flat upper surface of the floor panel supports of a corresponding base floor web tile assembly. Each floor panel has a recess in its upper surface at each corner. The corner recess accommodates the width of the flat upper portion of the panel fastener. When the panel fastener is screwed into the plastic boss of the floor panel support, it secures the recessed corner of the floor panel therebetween. In this way, the panel fastener simultaneously secures the corners of four adjacent floor panels, thereby locating and evenly spacing the floor panels on the surface of the interconnected base floor web tile assemblies. Further, the panel fasteners are also constructed with sufficient tolerance to allow for small inconsistencies in the raised floor level. Thus, upon proper installation, the upper surface of the panel fastener is substantially flush with the upper surface of the floor panel and the lower surface of the floor panel is secured against the upper surface of the floor panel support.
The raised floor system of the present invention is installed on a base floor in what is described as a xe2x80x9ctop-downxe2x80x9d process. Once the base floor web tile assemblies are interconnected, to cover the base floor in its entirety or any portion thereof, the assemblies need not be lifted to apply adhesive, i.e., the xe2x80x9ctopxe2x80x9d (upper surface of the base floor web tile assembly) remains xe2x80x9cdownxe2x80x9d (installed on the base floor) during application of the adhesive. A row of base floor web tile assemblies are laid down on the base floor and interconnected by interconnection means located along the perimeter of each base floor web tile. Mastic is then injected through the apertures of the adhesion pads that extend from each connection pod and docking pod of the base floor web tile. The mastic then fills the area created by the raised radial lines under the adhesion pad. Raised floor panels are then secured by a panel fastener to the upper surface of the base floor web tile assemblies as previously described. The area created by the radial lines under the adhesion pad retains mastic even after the weight of the floor panels is applied thereby assuring adhesion of the base floor web tile assembly to the base floor.